1. Field of the Invention
This invention relates to a platinum complex having a superior antitumor activity.
2. Description of the Background
Cisplatin, which is a platinum complex reported by Rosenberg et al. as a novel antitumor agent in 1969 [Nature, 222, 385 (1969)] has a wide antitumor spectrum and is used especially as a antitumor agent exhibiting a remarkable effect particularly on genitalia cancer, bladder cancer, and head and neck cancer, or the like. There are a number of studies on platinum complexes other than cisplatin. They are reported for instance in Japanese Patent Laid-open No. 31648/1978, Japanese Patent Laid-open No. 77694/1982, and the like.
The aforementioned cisplatin is commercially sold as a antitumor agent. The compound, however, has a high toxicity to kidney and other organs, and thus a limitation is imposed to its use. The purpose of the invention is to provide a platinum complex with a superior antitumor activity and yet exhibits a lower degree of toxicity.
The inventors have synthesized various platinum complexes having 1,3-diamino-2-propanol as a ligand and studied their pharmaceutical effects. As a result, the inventors have found that a platinum complex represented by the following formula (I) has advantages of a superior antitumor activity, a low toxicity, and high solubility in water. The finding has led to the completion of this invention.